不同增殖能力结肠癌细胞株iNOSmRNA表达的比较研究

Comparison of iNOS mRNA expression in colorectal carcinoma cell strains with different proliferation protentials

目的 :探讨诱导型一氧化氮合酶 (iNOS)mRNA在结肠癌不同增殖能力细胞株中的表达和作用 ,研究全反式维甲酸 (ATRA)对于结肠癌不同增殖能力细胞株iNOSmRNA表达的影响。方法 :采用MTT方法确定结肠癌细胞株CW - 2和LS174T的生长增殖状况 ,用RT -PCR和Northernblot方法检测结肠癌中iNOSmRNA的表达量。结果 :MTT生长曲线显示结肠癌细胞株LS174T的生长增殖比CW - 2快 ;RT -PCR显示CW - 2细胞株有较强的iNOSmRNA表达 ,而LS174T细胞株iNOSmRNA的表达较弱 ;Northernblot检测在CW - 2中有明显的iNOSmRNA表达 ,但在细胞株LS174T中表达相对较弱 ;ATRA对结肠癌CW - 2和LS174T细胞株iNOSmRNA的表达量无明显影响。结论 :iNOSmRNA对结肠癌细胞株生长有双重作用 ,即在低增殖结肠癌CW - 2呈高表达 ,可以通过细胞毒或诱导细胞凋亡等作用发挥抗肿瘤效应 ;在高增殖结肠癌LS174T呈低表达 ,产生NO作为信号转导的重要分子 ,增加血供和血管生成 ,促进肿瘤生长、侵袭和转移。ATRA可以抑制结肠癌细胞株的生长。

AIM: To evaluate the expression of iNOS mRNA in different invasion ability colon carcinoma cell strains. METHODS: MTT was used to detect the growth and reproduction of colon cancer cell strain CW-2 and LS174T. RT-PCR and Northern blot were used to detect expression of iNOS mRNA in colon cancer. RESULTS: MTT growth curve displayed that colon cancer cell strain LS174T grew and reproduced faster than cell strain CW-2. RT-PCR showed that iNOS mRNA expressed strongly in CW-2 cell strain, while iNOS mRNA expressed weakly in LS174T cell strain. Northern blot detected that iNOS mRNA expressed obviously in CW-2 cell strain, but cell strain LS174T have no obvious iNOS mRNA expression. All-trans retinoic acid (ATRA) had no obvious effect on iNOS mRNA expression in CW-2 cell strain of colon cancer. CONCLUSIONS: ATRA has no obvious effect on iNOS mRNA expression. iNOS has a dual effect on tumor growth. In low-metastatic colon carcinoma CW-2, iNOS may exert a anti-tumor influence by cytotoxicity or inducing cell apoptosis. In high-metastatic colon cancer LS174T, iNOS produced low concentration of NO, which may be an important signal-transduction molecule for increasing blood supply and angiogenesis, which improve the growth, invasion and metastasis of tumor.